Haeckel’s embryos: fraud not proven

Through the last half of the nineteenth century and the first part of the twentieth, no scientist more vigorously defended Darwinian theory than the German Ernst Haeckel (1834–1919). More people learned of the new ideas through his voluminous publications, translated into numerous languages, than through any other source, including Darwin’s own writings. He enraged many of his contemporaries, especially among the religiously orthodox; and the enmity between evolutionary theory and religious fundamentalism that still burns brightly today may in large measure be attributed to Haeckel’s unremitting attacks on the ingressions of religion into science. Though he retained a life-long friendship with and the support of Darwin, some in the scientific community who were critical of evolutionary theory—Emil Du Bois-Reymond, Rudolf Virchow, and Louis Agassiz, for instance—accused him of deception. That charge has been renewed in our time based on seemingly incontrovertible evidence. In a Science magazine article published in 1997, ‘‘Haeckel’s Embryos: Fraud Rediscovered,’’ Haeckel, was indicted of having intentionally misrepresented embryological development (Pennisi 1997). The article reported that the work of Michael Richardson and his colleagues demonstrated this malfeasance through a comparison of Haeckel’s illustrations of early-stage embryos with photographs of the same species at a comparable stage (see Fig. 1). The photos showed embryos of various species that differed among themselves and certainly from Haeckel’s images. The differences were striking and the implication obvious: fraudulent misrepresentation. Richardson, as quoted in the article, affirmed the charge: ‘‘It looks like it’s turning out to be one of the most famous fakes in biology’’